Dihydroxy bis-sulfides are sulfur-containing organic compounds having many uses. One desirable feature of these compounds is their emulsifying capability. Dihydroxy bis-sulfide compounds may be used as intermediates for preparing fatty acid esters, as monomers for polysulfide rubbers, as cross-linking agents for polyesters and polyurethanes, as lubricant additives, and as emulsifying agents for photographic silver halide systems.
The prior art discloses preparing dihydroxy bis-sulfides by a reaction of sodium salt of monothioglycol with ethylene bromide and by a reaction of ethylene chlorohydrin with the sodium salt of ethylene dithioglycol, as described in J. Amer. Chem. Soc., Vol. 44, p. 634-636 (1922). These processes, however, produce a low purity, low yield bis-sulfide product.
Alternative processes for preparing a higher yield of dihydroxy bis-sulfide compounds are desirable, especially those processes providing a high purity, high yield product. Further, it would be desirable if a process could be developed where the product could be easily isolated from the reaction mixture.